1. Field of the Invention
The present invention relates to an endoscope in which a cover is attached to a distal end member configuring a distal end portion of an endoscope main body.
2. Description of the Related Art
There has been known an endoscope in which a high-frequency treatment instrument is used. The endoscope of this type has structure in which, in order to safely use the high-frequency treatment instrument, a surface of an elongated insertion section is coated with an insulative resin material, an insulative rubber member is further disposed in an exterior portion of a bending section disposed on a distal end side of the insertion section, and a cover formed of an insulative material is attached to a distal end member configuring the distal end portion of the insertion section to insulate the entire insertion section of the endoscope. Since the distal end member is rigid, by attaching the cover, when an insertion section distal end is inserted into a bent body cavity of a human body or the like, even if the insertion section distal end touches a body cavity inner wall, it is possible to protect the body cavity inner wall from damage.
When safety is taken into account, the cover is desirably fixed to the distal end member by an adhesive. However, the endoscope needs to be sufficiently cleaned and disinfected after use. For example, when a mechanical component such as a raising base for raising a treatment instrument is housed in the distal end member, gaps among respective components are narrow and cleaning work takes time.
Therefore, for example, Japanese Patent Application Laid-Open Publication No. 2010-253061 discloses an endoscope in which a cover is enabled to be attached and detached, in cleaning and disinfection, the cover is detached from a distal end member to make it easy to clean both of the cover and the distal end member, and the cover can be attached to the distal end member after the cleaning.
In the endoscope disclosed in the literature, a guide groove extending from a distal end side in a proximal end direction and bending in a J-shape on a proximal end side is provided on a side surface of an end portion and, on the other hand, a convex section engaging with the guide groove is provided on an inner wall of the cover. That is, in a state in which the convex section of the cover engages with the guide groove, when the cover is attached to the distal end member, the convex section is guided by the guide groove to move. A projecting section protrudingly provided in the distal end member presses and elastically deforms an inner surface of the cover. At that point, the convex section has reached a J-shaped bending part of the guide groove. Therefore, by slightly returning the cover, the convex section hooks on a J-shaped bending end portion of the guide groove to be positioned and fixed.